In nature, wind energy is an energy source that is renewable, pollution-free and of large reserves. Along with global warming and energy crisis, development and utilization of wind energy are sped up to minimize the discharge of greenhouse gases such as carbon dioxide in various countries, so as to protect the earth we live upon. Utilization of wind energy is mostly in forms of wind power and wind power generation, in which the wind power generation is predominant.
Currently, an offshore wind turbine set comprises four parts: a foundation, a tower column, a wind turbine head and blades, which are transported to the offshore construction site by a transportation vessel and are separately constructed and installed, and the test of the complete set is finished. Structure type employed by the offshore wind turbine foundation in construction is generally mono-pile foundation, multi-pile foundation, gravity type and jacket type foundations. Methods of Installation include sectional hoisting and complete hoisting and so forth. The test is generally performed using offshore test, which results in a series of technical issues, for example, the transportation and installation of the offshore wide turbine set can not realize the integration, there is a interface between the transportation and the installation, and the construction in the shallow water is difficult, which increase the investment cost on the offshore wind turbine foundation construction in a larger degree than on the onshore foundation, thereby limiting the development of offshore wind power.
With reference to Chinese Invention Patent Application Publication No. CN101169108A, published on Apr. 30, 2008, which discloses an offshore wind turbine tower with structure of an integral design of wind tower foundation and the wind turbine tower frame and the generating set. The offshore construction of the offshore wind turbine tower is completed with a one-step installation of the whole wind turbine tower. The offshore wind turbine tower of the present invention has a bottom that is mono-cylinder suction anchor foundation or multi-cylinder suction anchor foundation, and a ballast tank is provided on the top of the suction anchor which adjusts the center of gravity of the entire offshore wind turbine tower by filling steel emery therein, and controls the center of gravity of the entire wind turbine tower on the suction anchor foundation, so as to readily reverse the wind turbine tower under the gravity from a horizontal position to a vertical state for the convenience of sinking during installation. However, the wind turbine set is stored in a toppled state during transportation which is different from the state during use of the wind turbine set, and possibly causes damage to the precise wind turbine set. In addition, when the large scale posture transition from a vertical posture to a horizontal posture is performed, it not only requires higher structural strength of the wind turbine tower but also needs large specific equipments for operation and is possibly even inoperable for a large wind turbine tower.
Therefore it is necessary to make improvement to overcome the existing technical problems.